The present invention relates generally to the drive system for a material handling implement. More specifically it relates to a mechanism for engaging and disengaging a drive shaft and driven elements on a forage wagon or similar tractor drawn implement operable by the tractor power take-off.
On the conventional type of material unloader used for transporting forage, hay and the like, there is generally provided an apron chain, beaters and a cross conveyor operated by a power shaft having a clutching mechanism. For reasons of safety and convenience a safety trip mechanism is located near the front of the implement to trip the clutch and disengage the power shaft from the various drives. In the case of previous forage wagons, tripping or disengaging the clutch left part of the drive system and at least one of the mechanisms such as the cross conveyor in operation. If a large clump of material fell in the cross conveyor, the operator often could not shut down the drive in sufficient time to prevent jamming.
Previous systems employed a jaw clutch which could not be engaged while the power shaft rotated. This type of system was expensive to manufacture, and occupied a considerable amount of space. Further, after tripping that type clutch, the operator had to go to the tractor to stop the power shaft and then return to the implement to re-engage the mechanism. This jaw clutch additionally projected outwardly, increasing space requirements and posing a hazard when shielding was removed.
On conventional wagons, a trip lever or bar is provided as the control to release the clutch and disengage the drive shaft from the various driven mechanisms. Tripping the clutch required movement of the bar or lever in a specific direction, usually toward the operator. In certain situations where immediate shut-down was desired, the operator could not conveniently move the bar or lever in the proper direction to operate the mechanism and disengage the driven elements.